Musings on Buddhism and modern global culture, plus a few miscellaneous topics.

Thursday, 29 October 2009

Consciousness and mind are not emergent phenomena or emergent properties of the brain.

Summary: The mind cannot be an emergent property of the brain or any other physical system, since emergent properties and emergent phenomena are psychological in origin, and require the pre-existence of an observer's mind in order to become manifest.

'Emergence - Properties of a complex physical system are emergent just in case they are neither (i) properties had by any parts of the system taken in isolation nor (ii) resultant of a mere summation of properties of parts of the system.

Thus a boat which drifts northwestwards in response to a southerly wind and a current flowing from the east is not exhibiting emergent behavior, whereas the products of chemical reactions could be considered emergent. To quote the Dictionary of Philosophy of Mind:

"Consider the following chemical process: CH4 + 2O2 --> CO2 + 2H2O (Methane + oxygen produces carbon dioxide + water). For Mill, the products of such chemical reactions are not, in any sense, the sum of the effects of each reactant.

While the mechanics underlying chemical reactions are understood well enough today to render Mill's point dubious, we can see why the above chemical reaction would impress Mill and his contemporaries as significantly different in kind from the Composition of Forces for moving bodies. In the case of the chemical reaction, the resulting compounds exhibit properties significantly different from those of the reactants. For instance, methane is violently combustible, whereas carbon dioxide and water are not.

This contrasts sharply against the case of a north-westerly moving object being propelled by two forces--one towards the north, the other towards the west--insofar as the subsequent motion is so obviously decomposable into the effects of the conjoint causes. A very live possibility to consider in connection with these examples is that an enhanced understanding of the processes that underlie some observed property of a system may show that system not to be an example of emergence.

That is, an increase of knowledge about the way certain effects are obtained may reveal that certain effects are decomposable into the effects contributed by subcomponents of that system. Mill's chemical examples fail as properly emergent for just this reason. With the development of quantum mechanical explanation, we have been able to see how chemical reactions are composed of additive properties of individual electrons (McLaughlin, 1992, p.89)."

Note that in the case of a chemical reaction, the attribution of emergence differs according to the extent of knowledge of the observers (19th century bucket chemists versus 20th century quantum physicists).

Nevertheless, it is still commonplace to think of certain phenomena, such as biological systems, as as showing complex behavior which somehow emerges uncreated out of far simpler behaviors such as the chemistry of carbon compounds.

The Game of Life as an emergent phenomenon.

One of the most familiar examples of emergent behavior is exhibited by cellular automata, such John Conway's Game of Life and its variants (eg Brian's Brain). These are available as animations on the web:

The Game is what a computer programmer would nowadays define as an object, which consists of a datastructure (the two dimensional pixel array) and associated algorithms (the rules which determine whether pixels switch on or off according to the state of their neighbors).

The algorithms are extremely simple:

A dead cell with exactly three live neighbors becomes a live cell (birth).

A live cell with two or three live neighbors stays alive (survival).

In all other cases, a cell dies or remains dead (overcrowding or loneliness).

Amazingly, out of these simple rules operating on a simple datastructure, a complex system of gliders, oscillators etc appears.

But is this really an emergent phenomenon? If the gliders were to emerge out of the screen and glide around the top of our desk (as distinct from being pixel patterns gliding around our PC desktop), then we should have to concede that something had emerged. But all we can say is that an appearance has emerged.

So, from where has the appearance emerged?

If we search carefully, we come to the conclusion that we cannot find the complex behavior within the object. The movements of the pixel-structures are algorithmically compressible, with no remainder, back into the rules that generated them. There is no mysterious addition of procedural complexity.

The two-dimensional pixel array remains an array of pixels in two dimensions - it hasn't suddenly changed its nature and become a cube or magically sprouted chess-pieces.

Yet we can't deny that we have observed a phenomenon which has properties which 'look different' and 'feel different' from its constituents.

But if the phenomenon hasn't emerged from the object, then the only other place from which it could have emerged is the mind of the observer. We are therefore left with the conclusion that emergence is a psychological, not a physical phenomenon. The pixel array is 'nothing but' sequentially illuminated squares on the computer screen. All else is imputed by mind.

"The notion of reduction is intimately tied to the ease of understanding one level in terms of another. Emergent properties are usually properties that are more easily understood in their own right than in terms of properties at a lower level. This suggests an important observation:Emergence is a psychological property. It is not a metaphysical absolute. Properties are classed as "emergent" based at least in part on (1) the interestingness to a given observer of the high-level property at hand; and (2) the difficulty of an observer's deducing the high-level property from low-level properties"Similarly...
"The properties of complexity and organization of any system are considered by Crutchfield to be subjectivequalities determined by the observer.

"Defining structure and detecting the emergence of complexity in
nature are inherently subjective, though essential, scientific
activities. Despite the difficulties, these problems can be analysed in
terms of how model-building observers infer from measurements the
computational capabilities embedded in non-linear processes. An
observer’s notion of what is ordered, what is random, and what is
complex in its environment depends directly on its computational
resources: the amount of raw measurement data, of memory, and of time
available for estimation and inference. The discovery of structure in an
environment depends more critically and subtly, though, on how those
resources are organized. The descriptive power of the observer’s chosen
(or implicit) computational model class, for example, can be an
overwhelming determinant in finding regularity in data."(Crutchfield 1994) " from Wiki

So we can dismiss all claims that consciousness, mind and awareness are emergent properties of matter or brains, because we need the presence of a mind for emergent properties and phenomena to appear in the first place. The subjective activity of the mind of the observer, together with the 'objective' procedures and the structures upon which they operate, is an irreducible component of emergent phenomena.

The behavior of cellular automata gives a vivid illustration of the three levels of dependent relationship, as discussed in the article on Buddhist teachings on sunyata :

(1) Gross dependent relationship - the dependence of phenomena on their causes (the algorithms or rules of production).

(2) Subtle dependent relationship - the dependence of phenomena on their perceived parts (the pixels which go to make up the emergent structures).

(3) Very subtle dependent relationship - the dependence of phenomena on imputation by mind.

Emergent all the way up and all the way down?

In addition, the article on sunyata demonstrates that instead of viewing the world in terms of 'things', we should understand all phenomena in terms of three types of relationships - causal, organisational and imputational.

The universe consists of relationships and only relationships. To ask what the participants in these relationships are in themselves only leads to paradox.

One interesting aspect of emergent phenomena is the different causal and organisational relationships which appear at different levels of investigation.

For example, ecology emerges out of biology, which emerges out of chemistry, which emerges out of physics, which emerges out of mathematics, which emerges out of the mind contemplating the empty set.

Each level of investigation has its own explanatory relationships, yet if we check carefully there is no 'added extra' coming from the side of the objects. (Everything is algorithmically compressible without remainder, there are no mysterious ingredients added as we progress from lower levels to higher levels).

The only place from which these relationships/phenomena can emerge is the mind. Hence we are again forced to conclude that these emergent phenomena are psychological phenomena.

So, even the relationships themselves are imputed by mind and have the nature of mind.

2 comments:

thanks for an interesting article. I have not thought about emergence for a long time, but I am not really sure it can be waived away as psychological so easily. Take vision for example. Of course, ultimately photons are involved, but they are not the only class of phenomenon that is involved. And the behaviour of the photons within the visual system (or the electrochemical reactions within the visual cortex) are in no way different from their behaviour in every other system. As a result the photons are not the only reason why the visual system works, and an appeal to emergent properties to describe the system is not merely because we need to explain it; they also form part of the function of the system.

Thank for the article. I had a related thought recently. It goes something like this. The "emergence" view of consciousness is based on a particular world view, that can be simplified as saying that the world is like a collection of billiard balls. Now, the billiard balls can have lots of different sizes, and can contain smaller billiard balls, and can carry particular qualities and transfer those qualities to one another when they bump into each other, or combine or split apart. So even the most complicated electronic microcircuit, plant cell or living brain is just a collection of these billiard balls. And if we just make them collide, split, combine and exchange qualities in a complicated enough way, consciousness will be created.

The problem isn't about what might emerge *on top* of the collection of billiard balls. The problem is what the billiard balls *are made of*. It's not so much that we can't see down to the smallest level of billiard balls, or that the billiard balls sort of smear out into energy fields along the way down. The real problem is that the billiard balls sort of wink in and out of existence at the smallest scale. This is the Buddhist phenomenon of subtle impermanence, represented in quantum mechanics as the field of virtual particles that constantly come in and out of existence. This is a much more difficult notion from an "everyday perception" standpoint than the wave-particle collapse due to the act of observation. This is just completely baffling to the "billiard ball" view of the world. This is where Nagarjuna invites us to marvel at how the world can work at all without inherent existence, and yet still does.

To assert that consciousness emerges from the billiard balls does not merely overlook the fact that the billiard balls are in some way created by consciousness. It completely ignores the fact that we don't really understand how the billiard balls exist at all, and indeed that "billiard ball" is so obviously just a conceptual designation, which has no functional reality capable of causing anything to "emerge".

It's not even like the gliders in the game of life flying off the computer screen. It's like a conversation about the game of life in which we just casually assert that the gliders fly off the computer screen.